The OTR Cylinder Head Assembly for Cummins ISX15 SOHC ensures Expertise Built In™, boasting 30% more coolant flow to keep your engine cool in harsh environments. This heavy duty engine cylinder head assembly is essential to the airflow in and out of the cylinders as well as fuel deployment. This replacement cylinder head equips your heavy duty truck with new parts, including an all new valve train, cam bearings, injector tubes, and valve guides, giving you a smooth ride with optimal performance on the road ahead. FleetPride is your First Click in Heavy Duty®.